If you love houseplants you’ve probably come across them – those tiny little annoying flies that flit around the soil, seem to enjoy flying straight into your face and keep multiplying, no matter how many you manage to squish. They’re fungus gnats, or sciarid flies, and they like to live in damp compost. They’re usually more annoying than damaging – in any case you probably want to get rid of them.
As it’s currently Houseplant Week here in the UK, I thought I’d share with you my top tip for controlling those irritating little beasties: let nature give you a hand by getting yourself some Drosera capensis, or sundews. These are carnivorous plants with small, sticky leaves which capture insects, like fungus gnats, breaking them down and absorbing the nutrients through their leaves. I currently have three small plants which rotate to different areas of the house, depending on where the latest infestation is taking place.
Caring for Sundews
They like lots of light and are happy in full or part sun. Their main requirement is moisture – specifically rainwater, which is better for them than tap water. They’re often found growing in boggy or wet conditions in the wild, so to keep them happy indoors, stand them in a tray or saucer of rainwater to keep the soil consistently damp. I’ve learned this the hard way, having killed a few with my sporadic approach to watering, but I now have a water butt close to the house, making it easier to access rainwater when I need it. Now I just need to remember to keep those saucers topped up…
Sundews are a bit more dormant in the winter, when a few leaves might go brown and die off, but they should bounce back with new growth in the spring, and can produce one or two really pretty, dainty flowers which are surprisingly long-lasting.
Where to get them
I have bought a selection of plants in the past from Hampshire Carnivorous Plants – unfortunately the last time I used them I discovered their packaging isn’t great, they seem to use A LOT of plastic. However I have received really healthy plants which are a good size and well labelled.
The excellently-named Little Shop of Horrors has a nice selection of varieties and collections (many currently out of stock – I assume that will be resolved when spring rolls around).
They’re also available from Wack’s Wicked Plants (again, stock is low but there are one or two different varieties available) and they can also be found at some of the bigger garden centres and suppliers, such as Thomson & Morgan and Crocus.
There are hundreds of different kinds of Drosera, some have red leaves, some long, elongated leaves, others are flat and round – look around until you find a style you like and go for it! I usually buy the fairly common Drosera capensis and I’ve also had success with Drosera aliciae, which has broader leaves with an attractive red tinge.
If you’re not keen to add to your houseplant collection or think sundews might be too high-maintenance for you, I’ve also managed to keep on top of fungus gnat infestations by using Sciarid Fly Nematodes which are tiny little microscopic organisms which release bacteria to kill the flies. (If you’re not squeamish about it, there’s a more detailed explanation of how they work here). All you do is mix the nematodes into water and then drench your houseplant soil to release them.
So there you have it – a useful plant to add to your collection. Not only does it help reduce fungus gnats but it’s also fascinating for adults and children (if you don’t mind watching flies being digested!) – and it’s attractive too.
Other good stuff…
📖 I’m reading my way through this in 2024 and loving watching the micro-seasons unfold
🎧 This series is an interesting listen for anyone interested in a career in horticulture
🌱 They’ve found new plants in the world! Nature is amazing.
Julianne Robertson 